Cubic boron nitride films were deposited on (100) silicon substrate using r.f. plasma chemical vapor deposition (CVD) thermally by a tungsten filament. The films obtained were characterized by infrared absorption spectra and electron energy loss spectroscopy. Experimental results showed that the structure and quality of cubic boron nitride (c-BN) films strongly depended on the deposition conditions. The studies also indicated that the compressive stress in the films increased with h-BN content in the films, while interfacial region corresponding to the transition from h-BN to c-BN was found to be of very low stress value. P-type conductivity with promising values of the mobility in c-BN films has been found by Be-doped.